When you think about water pollution, you might think about massive sewer overflows, factory pollution or agricultural runoff. But there’s another source of water pollution that might be in your backyard: septic systems that have failed.

They pollute lakes and streams around the state – and in fact, around the country.

Sean Hammond, deputy policy director for the Michigan Environmental Council, is calling for better rules for septic systems and inspections.

“We are the only state in the country to not have a statewide septic code,” Hammond said.

"Septics are the one place where we are behind the entire nation. We are the last state to even consider adopting a statewide septic code. Every other state has one. And with our precious water resources, and fifty percent of our state getting their water from groundwater, we have to move forward on protecting those resources."

That means throughout most of Michigan, no one is inspecting septic systems once they're in the ground. Only 11 counties have any sort of requirement, he said, while the state's 72 other counties have none.

At the same time, the state estimates that septic systems are failing at a rate of ten percent.

When septic systems break, they can cause nutrient pollution, E. coli and other types of bacteria to find their way into groundwater and other waterways.

This is especially problematic, Hammond said, because about half the state gets its water from groundwater.

“Until we can get a registry and figure out where these septic systems even are, we really don’t even know what the true risk is, even though we know it’s probably great,” Hammond said.

He said House Bills 5732 and 5733 aim to establish a statewide septic code for Michigan.

“Septics are the one place where we are behind the entire nation,” Hammond said. “We are the last state to even consider adopting a statewide septic code. Every other state has one. And with our precious water resources, and 50% of our state getting their water from groundwater, we have to move forward on protecting those resources.”